From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S968899AbdDSSOS (ORCPT <rfc822;w@1wt.eu>);
        Wed, 19 Apr 2017 14:14:18 -0400
Received: from mail-yb0-f179.google.com ([209.85.213.179]:35985 "EHLO
        mail-yb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S968844AbdDSSOP (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 19 Apr 2017 14:14:15 -0400
Date: Wed, 19 Apr 2017 11:14:12 -0700
From: Matthias Kaehlcke <mka@chromium.org>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
        Mark Charlebois <charlebm@gmail.com>,
        Behan Webster <behanw@converseincode.com>,
        Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Grant Grundler <grundler@chromium.org>,
        Michael Davidson <md@google.com>, Greg Hackmann <ghackmann@google.com>,
        Peter Foley <pefoley2@pefoley.com>
Subject: Re: [PATCH] fs: compat: Remove warning from COMPATIBLE_IOCTL
Message-ID: <20170419181412.GF128305@google.com>
References: <20170404180720.182336-1-mka@chromium.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20170404180720.182336-1-mka@chromium.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

El Tue, Apr 04, 2017 at 11:07:20AM -0700 Matthias Kaehlcke ha dit:

> From: Mark Charlebois <charlebm@gmail.com>
> 
> cmd in COMPATIBLE_IOCTL is always a u32, so cast it so there isn't a
> warning about an overflow in XFORM.
> 
> From: Mark Charlebois <charlebm@gmail.com>
> Signed-off-by: Mark Charlebois <charlebm@gmail.com>
> Signed-off-by: Behan Webster <behanw@converseincode.com>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Resending https://patchwork.kernel.org/patch/4961631/
> 
>  fs/compat_ioctl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
> index 11d087b2b28e..6116d5275a3e 100644
> --- a/fs/compat_ioctl.c
> +++ b/fs/compat_ioctl.c
> @@ -833,7 +833,7 @@ static int compat_ioctl_preallocate(struct file *file,
>   */
>  #define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) & 0xffffffff)
>  
> -#define COMPATIBLE_IOCTL(cmd) XFORM(cmd),
> +#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd),
>  /* ioctl should not be warned about even if it's not implemented.
>     Valid reasons to use this:
>     - It is implemented with ->compat_ioctl on some device, but programs

Ping, any feedback on this change?

Thanks

Matthias